Optimization of harvest and storage time in cold storage for improving grape quality properties

In this study, optimization of quality properties of grape during cold storage was investigated by Response Surface Methodology (RSM). Effect of harvesting time in the ranges 5 - 35 days and cold storage time from 0 to 180 days on the flavor index, dextrose, total soluble solute, pH and acidity of Sorkh Fakhri Shahrood cultivar were investigated by Central Composite Design (CCD). Furthermore, the results showed that optimum conditions for harvesting and cold storage time were 18 and 123 days, respectively. At this optimum point, maturity index, dextrose, total soluble solute, pH and acidity were found to be 52.8, 277.06, 16.9, 4.12 and 0.32, respectively. Also, harvesting time after 5 days ripeness was realized as the worst conditions in order to preserve grape during 160 days.